To avoid wagon wheel pattern, normally I put more resist onto wafer
surface than needed. However, I can observe that much of the resist has
been spinned to the plastic bowl and wasted. I am just wondering how I
can decide the roughly enough quantity of resist, say for an 8-inch
wafer, neither too much nor too little.

Ziyang

-----Original Message-----
From: Robert Black [mailto:[email protected]]
Subject: RE: [mems-talk] Could someone tell me where I can get
someinformationabout wagon wheel pattern?

A wagon wheels patterns is a term referred to when not enough resist is
applied to the wafer. There are spikes at the edge of the wafer, where no
resist exists.  This makes the wafer resemble a wagon wheel. How many and
how big depends on how bad the problem is.